1. Field of the Invention
The present invention relates generally to surgical systems, methods, and instrumentation. The present invention relates more specifically to systems for tracking and locating objects and items utilized during surgical procedures in operating room environments as well as real time visualization and location of foreign objects in the body while on the operating table.
2. Description of the Related Art
Surgical procedures typically require the use of a large number of small objects and items that both the physician and other attending healthcare providers must manipulate during the surgical procedure. Many of these objects and items, because of their function, find their way into the patient undergoing the surgical procedure, where they serve to control the flow of fluids within the surgical wound site or to retract tissue within the surgical opening for the overall purpose of facilitating the surgical procedure. In most instances these objects and items are removed from the surgical wound prior to the process of closing the wound after the surgical procedure has been completed. Despite numerous precautions, such surgical items and objects continue to be left within patients, generally for failure to have properly tracked and accounted for each of the items utilized in the surgery.
Many efforts have been made in the past to provide systems for locating items and objects that might have been left within the surgical wound during and after the surgical procedures have been carried out. Most of these efforts have focused on providing x-ray opaque material in or on the objects and items associated with the surgical procedure, such that they might readily be identified through an x-ray image of the surgical area post-surgery. There are however a number of drawbacks to such systems including the requirement of positioning x-ray equipment in conjunction with the surgical sight as well as inaccuracies in the visual review of an x-ray image to locate what are often poorly discernable object images. While metal based surgical instruments are generally opaque to x-rays and can easily be seen, many surgical implements such as sponges and many newer plastic based instruments must be made radio opaque to x-rays by the incorporation of threads (barium impregnated threads, for example) or the attachment of some type of radio opaque tag to the item.
The primary problem, however, with such systems that rely upon x-ray images to identify objects that may have been left within the patient is the simple requirement of positioning x-ray equipment in proximity to the patient in advance of closing the surgical wound. In many cases, even after going through the process of setting up for x-ray imaging, the objects of interest are sometimes not even seen within the often poorly defined image. Such x-ray equipment remains generally quite large and cumbersome and difficult to manipulate in conjunction with a patient on the operating table. In addition, any excess exposure to x-rays is known to have detrimental effects to the patient and to those within the immediate area unless proper shielding is maintained in place. For all of the above reasons, those systems that rely upon x-ray imaging techniques to detect items that may have been left within the surgical opening provide less than desirable solutions to the problem.
Some efforts have been made in the past to develop systems that utilize detection methods other than x-rays to locate and identify objects and items that may have been left within patients undergoing surgical procedures. These efforts have more recently focused on the utilization of ultrasound and radio frequency electromagnetic waves to locate items used in surgical procedures. Systems that rely strictly on ultrasound imaging suffer many of the same problems that are associated with x-ray imaging in that an inspection and interpretation of the ultrasound image is required in order to identify and locate tagged objects. Radio frequency based systems that utilize tags identifiable through RF transmissions are less dependent on image interpretation but suffer from an inability of RF waves to penetrate through more than a few centimeters of tissue. Some of the systems that have been developed in the past that address these various approaches to locating surgical objects and instruments include systems described in the following issued U.S. patents:
U.S. Pat. No. 3,834,390 issued to Hirsch on Sep. 10, 1974 entitled Combination Neurosurgical Sponge describes an early attempt to tag surgical sponges by positioning an x-ray detectable object together with each sponge and wrapping the sponge and x-ray marker together with a layer of porous material.
U.S. Pat. No. 4,114,601 issued to Abels on Sep. 19, 1978 entitled Medical and Surgical Implement Detection System describes a method by which surgical implements, surgical instruments, surgical sponges, and the like may be detected within the human body or other areas of interest by incorporating or adding a radio-frequency transponder. Non-linear mixing of two frequencies in a radio-frequency transponder is used. The transponder may be a small film deposition of ferrite material exhibiting gyro-magnetic resonance at selected frequencies or a solid state device exhibiting similar properties.
U.S. Pat. No. 4,193,405 issued to Abels on Mar. 18, 1980 entitled Detectable Medical and Surgical Implements describes a variety of surgical devices and implements that may be detected within the human body by incorporating a radio-frequency transponder therein. In this case, the transponder is described as being a small film deposition of ferrite material exhibiting gyro-magnetic resonance at selected frequencies, or a solid state device exhibiting similar properties.
U.S. Pat. No. 4,658,818 issued to Miller, Jr. et al. on Apr. 21, 1987 entitled Apparatus for Tagging and Detecting Surgical Implements describes a system for tagging and detecting a surgical instrument accidentally left within a patient by way of a miniature electrical oscillator attached to each implement. The oscillator is activated before surgery begins. The detection methods include use of a handheld RF receiver or the use of ECG electrodes and instruments.
U.S. Pat. No. 5,107,862 issued to Fabian et al on Apr. 28, 1992 entitled Surgical Implement Detector Utilizing a Powered Marker describes yet another modification of the above Fabian et al., this time incorporating a battery-powered marker (as opposed to an acoustic marker) and further incorporating an antenna with field generating means to generate an electromagnetic field and thereby provide the marker with signal identity.
U.S. Pat. No. 5,112,325 issued to Zachry on May 12, 1992 entitled Surgical Sponge with Plurality of Radio-Opaque Monofilaments describes a surgical sponge structure particularly for neuro-surgical applications comprising a fibrous web having attached to one surface thereof a locator string comprising a bundle of x-ray detectable monofilaments. This system anticipates the use of x-ray devices to scan for the presence of such surgical sponges during and post surgery.
U.S. Pat. No. 5,329,944 issued to Fabian et al. on Jul. 19, 1994 entitled Surgical Implement Detector Utilizing an Acoustic Marker describes a method and apparatus for accurately and reliably detecting surgical implements within animal or human tissue. The apparatus comprises a detector responsive to the presence, within a wound, of a surgical implement to which a marker is secured. The marker is adapted to produce identifying acoustic signal characteristics within the wound.
U.S. Pat. No. 6,026,818 issued to Blair et al. on Feb. 22, 2000 entitled Tag and Detection Device describes a method and a system for the detection of unwanted objects in surgical sites. These objects are described as including medical sponges or other items used in body cavities during surgery. The detection tag is of minimal size with a length of about 8 mm in the shape of a bead (ovate or circular) and is constructed of a medically inert material. Further, the bead incorporates a single signal emitter, such as the combination of a miniature ferrite rod, a coil, and a capacitor element embedded therein. Also described is an alternate embodiment wherein the tag includes a flexible thread composed of a single loop of wire and a capacitor element. A detection device is utilized to locate the tag by pulsed emission of a wideband transmission RF signal. The tag resonates with a radiated signal in response.
U.S. Pat. No. 6,675,040 issued to Cosman on Jan. 6, 2004 entitled Optical Object Tracking System describes a camera system operable in conjunction with data processors and graphic displays to provide tracking of instruments, objects, patients, and other devices in a surgical setting. The objective is primarily to provide the physician with a constructed view of the patient's anatomy in relationship to a variety of surgical instruments. The instrument “tags” comprise a wide variety of visually distinguishable markers associated with each of the instruments.
U.S. Pat. No. 7,001,366 issued to Ballard on Feb. 21, 2006 entitled Radiologically Trackable Surgical Sponges describes an operating room-wide system that employs radio-opaque objects to count and account for surgical sponges. A container is structured to receive the surgical sponges and to be scanned by a radiation source (x-ray or the like) in a manner of counting the sponges as they are inserted into the disposal container. Connected computer systems are anticipated for maintaining the accounting records.
Efforts in the prior art have generally failed to realize a cost effective method for locating and tracking objects and instruments utilized in carrying out surgical procedures. Such systems developed in the past have proven to be less than desirable to implement, either because their implementation has been far too costly for the risks they seek to eliminate, or their implementation is far too cumbersome to carry out in connection with each and every surgical procedure within an operating room environment. The general problem as identified in the prior art is that very simple, easy to use systems, suffer from inaccuracy and unreliability; while reliable and accurate systems suffer from being overly complex and overly cumbersome to utilize.
It would be desirable, therefore, to have a system for tracking and locating objects and items utilized in surgical procedures that could carry out its functionality in a manner nearly transparent to the physicians and attending healthcare providers in the process of carrying out the surgical procedure. It would be desirable if much of the function of such a system could be carried out in automatic fashion such that interaction by the healthcare providers could be minimized. It would be desirable if a final check of the objects and items utilized in the surgical procedure would involve the review of a report from the system rather than the initiation of a locater function after the fact. It would be desirable if, at any point during the surgical procedure, attending healthcare providers could review the use and location of various items and objects and identify the mislocation or misplacement of any object earlier on in the surgical procedure.
It would be desirable if a system for locating and tracking objects and items utilized in surgical procedures integrated a two-stage process that resorted to focused location only when necessary. It would be desirable if, during the surgical procedure, items were tracked automatically by the system and only if any tracked items are “lost” during the surgical procedure, would a second stage in the process be implemented for isolating the location of the lost object and thereafter, through a much more narrowly focused identification process, locate the missing item so as to return it to a tracked status. It would be desirable if each of the above functions could be carried out in a system that was relatively unobtrusive to the surgical procedure and relatively cost effective to implement within the operating room environment.